Remote after-effects of resistive static contractions of lower trunk depressors and upper extremity on maximal active range of motion of ankle extension in ankle fractures

Abstract

Direct approaches to improve maximal active range of motion (MAROM) of restricted joints may be difficult because of pain or weakness of agonist and/or antagonist muscles. Resistive static contraction (SC) of posterior depressors (RSCPD) using a PNF pattern in the mid-range of pelvic motion increases the flexibility of remote joints, such as the upper shoulder and knee, as remote after-effects in the clinic. The purpose of this study was to investigate the remote after-effects of RSCPD on the MAROM of ankle plantar flexion in patients with isolated ankle fractures. Thirteen patients with ankle fractures (7 men and 6 women, mean age 50.9 years, SD 11.9 years) were randomly assigned to resistive SC of shoulder flexion on the affected side (SCUE), RSCPD on the affected side, and SC of the affected ankle extensors. Each SC was induced by resistance (20% MVC) generated by a manual force using a handheld dynamometer. The duration of each resistive exercise and stretch was 20 s. The % MAROM change for ankle extension after each technique was calculated by subtracting the MAROM before each technique. The mean (SD) MAROM was 3.32 (11.35)% for RSCPD, 0.64 (6.25)% for SCUE, and −5.65 (8.05)% for SC. A two-way Anova for the %MAROM change showed significant main effects for technique [F (2.24) = 3.84, P = 0.04, partial eta squared = 0.24] and individual ( P = 0.32). A post-hoc Scheffe test indicated that the % MAROM change for RSCPD was significantly larger than that for SS ( P = 0.04). RSCPD showed a significant improvement over SC, which suggests that RSCPD may have immediate remote after-effects that improve flexibility of the plantar flexor muscle in patients with ankle fracture.